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ABoxsterPetrolvsB420dDiesel
  • MotorwayMotorwayRange and charging
  • PerformancePerformance0-100, top speed
  • ConsumptionConsumptionYearly cost
  • SpecsBoxster · 420d

Porsche Boxster S vs BMW 420d Convertible G22

Trip mapped at a glance. Charging stops visible, total duration predictable. Caralogy simulation at 130 km/h.

sports car · 2012 vs 2021 · Paris → Marseille · 775 km · 130 km/h
PorschePetrol

Boxster S

314 ch · 2012

VS
BMWDieselPlus rapide

420d Convertible G22

190 ch · 2021

Simulation trip
Assumptions: 130 km/h · start réservoir plein · mild weather

Result · total trip time

APorsche Boxster S

7h16charging included

3 stops · 437.25 €

Gap15 minin favour of 420d Convertible
BBMW 420d Convertible G22

7h01no stop

0 stops · 72.32 €

Paris → Marseille · 130 km/h · Caralogy simulation
MeasureBoxster S420d Convertible G22Gap
Total time7h167h0115 min · 420d Convertible G22
Charging stops3 stops0 stops3 stops · 420d Convertible G22
Cost of energy used437.25 €72.32 €364.93 € · 420d Convertible G22

Visualise the trip

Both vehicles drive at 130 km/h. The difference comes from charging stops.

PorschePetrol
Boxster S
100%
221 km
Range
Paris
0 km · departure
Refuel 1
5 min · +58 L · 124.94 €
Refuel 2
5 min · +58 L · 124.94 €
Refuel 3
5 min · +58 L · 124.94 €
Marseille
775 km · Arrival 7h16
3
Stops
7h16
Duration
437.25 €
Cost of energy used
BMWDieselFastest
420d Convertible G22
100%
1372 km
Range
Paris
0 km · departure
Marseille
775 km · Arrival 7h01
0
Stops
7h01
Duration
72.32 €
Cost of energy used

The 15-minute lead of the 420d Convertible G22 does not come from driving speed, but from 3 fewer charging stops on this route (0 vs 3).

Both vehicles drove at 130 km/h for the entire trip. The gap is built at the stops: no stop for the 420d Convertible G22 versus 3 stops totalling 15 min for the Boxster S.

Motorway consumption: the Caralogy methodology

The official WLTP figures (10,7 L/100km for Boxster S and 4,5 L/100km for 420d Convertible G22) are measured on a mixed cycle averaging ~46 km/h. At a steady 130 km/h, aerodynamic drag weighs much more heavily - it grows with the square of speed. Caralogy calculates a motorway consumption specific to each vehicle based on its aerodynamic profile (SCx), weight and power curve - not a uniform correction factor. For this trip, the simulation yields 26,0 L/100km (Boxster S) and 4,3 L/100km (420d Convertible G22). Full methodology: see the assumptions below the controls.

Energy cost breakdown for your trip Paris → Marseille

The cost per kilometre depends on the electricity rate applied to each segment - based on the energy source used at that point of the trip.

Porsche Boxster S

SegmentEnergy usedDistanceConsumption€/kmCost (€)
Paris → Beaune, A6fuel · 2.17 €/L221 km58 L consumed0.565 €/km124.94 €
Beaune, A6 → Limonest, A6fuel · 2.17 €/L221 km58 L consumed0.565 €/km124.94 €
Limonest, A6 → Manosque, A51fuel · 2.17 €/L221 km58 L consumed0.565 €/km124.94 €
Manosque, A51 → Marseillefuel · 2.17 €/L111 km29 L consumed0.562 €/km62.43 €
Trip total437.25 €

BMW 420d Convertible G22

SegmentEnergy usedDistanceConsumption€/kmCost (€)
Paris → Marseillefuel · 2.17 €/L775 km33 L consumed0.093 €/km72.32 €
Trip total72.32 €

What produces these figures

WLTP combined consumption
10.7 L/100 km · 4.5 L/100 km
Fuel tank
64.0 L · 59 L

Compare with another vehicle

Replace one of the two with an alternative from the same segment

PorschePetrol

Boxster S

314 ch · 2012

BMWDiesel

420d Convertible G22

190 ch · 2021

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Frequently asked questions

On Paris → Marseille (775 km at 130 km/h), the 420d Convertible G22 arrives in 7h01 with 0 fuel stops.

WLTP consumption does not reflect motorway reality. Aerodynamic drag grows with the square of speed, so real consumption is 15 to 25 % higher than WLTP combined. Caralogy calculates a highway consumption specific to each vehicle based on its aerodynamic profile (SCx), weight and power curve.

Total time = driving time + charging time. Driving time is calculated at an average speed of 130 km/h on the motorway (adjustable). Charging time is calculated based on the real power curve of each vehicle, respecting the optimal 10 → 80 % range and the maximum power accepted by the chargers on the route.

No. The displayed cost covers only the energy consumed during the trip: kWh × energy rate, with a mix of home charging and DC fast chargers. Battery wear is a long-term ownership cost, not a trip cost.

On this trip, the energy used costs 437.25 € (Boxster S) and 72.32 € (420d Convertible G22). For reference, an equivalent BMW M340i (~9.5 L/100 km) would cost about 136 € in fuel.